Performance of interior spruce seedlings planted under dry soil and climatic regimes

• Main Author: Kostamo, Markku J.
• Language: English
• Published: 2009
• Online Access: http://hdl.handle.net/2429/6409

A soil water balance model was used in a retrospective study of the survival and performance of short-day treated interior spruce seedlings, operationally planted in the Prince George region under dry soil and climatic regimes in July and August, 1994. The soil water balance model has potential to be used in operational forestry as a tool in managing plantation sites that are susceptible to drought. Comparison of modeled and measured soil water content indicated that the model is able to predict soil moisture accurately if applied to sites where model assumptions are met. The model should be a good predictor of soil water content between early May and mid August for the Prince George region. A linear regression model was developed predicting seedling performance by soil moisture. The relationship between a seedling performance index and mean ϒm (soil matric potential) for 30 days following planting is strong, r²= 0.75. The best predictor of a root variable from above ground morphological measurements was found to involve a volume surrogate (caliper² x height) as the independent variable and dry root mass as the dependent variable, r² = 0.50. Site characteristics were found to be a good predictor of seedling survival, r²2 = 0.64. An additional seedling study showed that percent survival has a strong relationship with the modelled mean ϒ for 30 days following planting. Survival decreases substantially below a mean ϒm of -0.2 MPa.